NHMRC CEO Professor Warwick Anderson responds to recent comments on Croakey about environment and the Australian Dietary Guidelines.
During the four years over which the Australian Dietary Guidelines were drafted, attacks on the contents came from many quarters. There are many vested interests so these attacks were not unexpected. The most effective means of countering such attacks is to base guidelines firmly on evidence.
The Guidelines were based on examination of around 55,000 individual pieces of evidence and were assisted by advanced modelling. This modelling was undertaken so that the guidelines could talk about foods, rather than ingredients, and therefore were more understandable to readers seeking guidance – clearer and more practical that previous versions.
For the first time for NHMRC’s public health guidelines, we used an approach analogous to that used for clinical guidelines. That is, we considered around 55,000 pieces of evidence and inclusion/exclusion criteria were applied. Data was extracted from the included studies and assessed, with the body of evidence for each research question graded as excellent, good, satisfactory or poor according to rigorous systematic literature review methodology and standard NHMRC protocols. Criteria were then used to make recommendations based on this body of evidence (for example, , there being at least 5 confirming independent pieces of quality evidence, and the studies focussing on foods, not nutrients ). This rigour was the bulwark of our defence against the vested interests, who tend to rely on one or two favoured pieces of evidence.
The guidelines are aimed at health professionals such as general practitioners and dieticians and therefore the issue of social equity was covered with this audience in mind. While there is a relevant appendix, the ‘practical considerations’ and ‘practice guide’ sections of each main Guideline chapter cover considerations for particular groups (e.g. lower socioeconomic status) where relevant. Most importantly, development of the underlying advice took social equity considerations into account, for example in the modelling of dietary patterns and the range of foods depicted on, and flexibility of, the ‘Food Plate’.
As far as the environmental impact of food choices was concerned, we were certainly aware of its importance and that patients and clients increasingly approach their health professionals with a concern about the environmental impact of their choice of food.
Early attempts to include recommendations on the sustainability of food choices were questioned by the Council of NHMRC as lacking a level of evidence rigour comparable to that of the main Guidelines as described above. Other government agencies pointed out that specifically Australian evidence was often lacking, with farming practices here differing markedly to those in Europe and the US where most evidence is from. Secondly, there are many factors that influence environmental sustainability (such as emissions, water use, soil degradation, energy use, storage and transport), but many studies tended to concentrate on a subset of these factors, making it hard to draw rigorously evidence-based overall conclusions. In short, the state of the Australian evidence and the complexity of issues outside the health arena were such that more work is needed in order to provide recommendations at a comparable level of evidence as for the main dietary advice.
So, more work is needed. For this reason, I have asked my staff to continue liaising with the other government agencies on the current status of evidence on dietary choices and the environment, agreed definitions of key aspects, and practical strategies and approaches for Australians. I am very hopeful that this can yield similar strongly evidence based advice in the future. As we have learnt in the last three years, resisting the claims of vested interests is best based on the most rigorous evidence available.
Meanwhile, as the new Australian Dietary Guidelines state, not eating too much, not wasting food, eating a wide range of nutritious foods from the five food groups and limiting our intake of the foods mentioned in Guideline 3 can contribute to limiting our environmental impact.
The Dietary Guidelines are supported by the Eat for Health website. On this website, the sections on companion resources, food essentials, eating well and the eat for health calculators all contain material that may be of interest to Croakey readers.